Your tax return form is a 1040A. Your Social Security income is being reported on a SSA1099. If Social Security is your only income, you do not have to file a tax return. If your only income is the Social Security then the tax return form is showing that you have "zero" taxable income, and a zero income tax form cannot be e-filed. If you really really just want to file a tax return for some reason, then enter $1.00 of interest so it will let you e-file. Otherwise, you do not even really need to file.